Lymphotoxin beta receptor (referred to herein as LT-β-R) is a member of the tumor necrosis factor family which has a well-described role both in the development of the immune system and in the functional maintenance of a number of cells in the immune system including follicular dendritic cells and a number of stromal cell types (Matsumoto et al., Immunol. Rev. 156:137 (1997). Known ligands to the LT-β-R include LTα1/β2 and a second ligand called LIGHT (Mauri et al. Immunity 8:21 (1998)). Activation of LT-β-R has been shown to induce the apoptotic death of certain cancer cell lines in vivo (PCT/US96/01386). Treatment with specific humanized anti-LT-β-R antibodies that bind to LT-β-R and has minimal immunogenicity to its subjects, would thus be useful for treating or reducing the advancement, severity or effects of neoplasia in subjects (e.g., humans).